Minecraft shader problem?

I take a shader in and there's a line something like a rectangle on my screen you only recognize when you look at the sky you can see the cloud that is halfway and there's this line that removes all clouds and only shows the sky blue in the area in the rectangle how do I get it away?

Maybe it's because of the shader. Is it the same with everyone?

Yes

Use another shader.

Custom sky off and use vbos on